1. Field of the Invention
The present invention relates to a method and apparatus for managing digital content, and more particularly, to a method and apparatus for managing digital rights management (DRM) content for which a usage period is predetermined.
2. Description of the Related Art
Digital content has a characteristic in that it can be copied without loss unlike analog data, and it can be easily copied, reused, processed, and distributed. However, since authoring of the digital content requires much cost and time, illegal copying and distribution of digital content causes problems. In order to protect digital content and content authors from illegal copying, research on digital rights management (DRM) has been actively carried out, and many services using DRM have been introduced.
DRM is a technology that safely protects the rights and profits of content providers, prevents illegal copying, and supports the generation of digital content and management of distribution, including billing and payment agency services. According to conventional technology, a license includes a usage condition for a machine or person to read, and in order to prevent modification of the condition, an electronic signature is added and then, transmitted. The usage condition includes a valid period, the number of times reproduction is allowed, a maximum continuous reproduction time, a total reproduction time, reproduction quality, etc.
If a user obtains a license in order to access digital content, a DRM system examines a usage condition specified in the license, and if the usage condition is satisfied, the DRM system executes the digital content requested by the user. If the condition of a valid period in the usage condition is not satisfied, for example, if the valid period expires, the digital content stored and used in the user terminal apparatus may be deleted or processed in another way, and thus the user cannot use the digital content any more.